The present invention relates to fluid power valve assemblies. More specifically, the present invention is directed to a pneumatic valve assembly which includes a visual indicator including a light pipe to indicate actuation of a valve.
Fluid power valves of the prior art are constructed to have a visual indicator. These valve manifolds may include pneumatic valves having a light-emitting diode which is used as a light source to indicate that a particular valve is activated. Typically these valves include a LED positioned on the surface of a housing so that it is visible to the operator. These visual indicators assist in the maintenance and troubleshooting of the valve. The user can easily see whether the valve is actuated by using the visual indicator. However, in some valve arrangements, the LED may be partially obscured or not visible by the user due to its placement directly on the housing.
U.S. Pat. No. 4,418,720 to Day et al. discloses a solenoid operated valve including a light assembly 106 mounted to a valve with a lamp 112 located within an enclosure 114. The light assembly 106 further includes a light pipe 108 and a lens 110 at the opposite end so that the light emitted from the lamp 112 can be transmitted through the light pipe 108 to the lens 110 on the outer surface of the enclosure 114. However, a disadvantage with this design is that the light assembly 106 is connected to the valve assembly and in order to change or replace the lamp 114 or light pipe 108, the outer enclosure 114 must be removed.
Current designs of light pipes for valves are integral with the valve and difficult to replace when needed. The prior art valve design, such as the Day et al. design, uses a light pipe which is permanently installed within the housing 114. Other designs of light pipes are either fixed in place using a permanent glue, press fit or other permanent method thus making replacement of the light pipe difficult and time consuming. In addition, typically the replacement of the light pipe includes the added step of disassembly of the valve itself so that the valve cannot be used, further increasing down time of the equipment.
It would be desirable to provide a valve assembly having a visual indicator that can easily be replaced without the use of tools or disassembly of the valves themselves. It would be further desirable to provide a valve assembly having a modular design where multiple parts can be removed without the need for interrupting the operation of the valve itself.